Execution of "extractPage -v" returns this error => NameError: name 'version' is not defined

[jmorenobl]

python -m wikiextractor.extractPage -v
Traceback (most recent call last):
File "/Users/jorge/.pyenv/versions/3.8.2/lib/python3.8/runpy.py", line 193, in _run_module_as_main
return _run_code(code, main_globals, None,
File "/Users/jorge/.pyenv/versions/3.8.2/lib/python3.8/runpy.py", line 86, in _run_code
exec(code, run_globals)
File "/Users/jorge/.pyenv/versions/corges/lib/python3.8/site-packages/wikiextractor/extractPage.py", line 118, in
main()
File "/Users/jorge/.pyenv/versions/corges/lib/python3.8/site-packages/wikiextractor/extractPage.py", line 110, in main
version='%(prog)s ' + version,
NameError: name 'version' is not defined

[jmorenobl]

I have created this fix #259